San Miguel Xicalco Wastewater Treatment Plant, Ciudad de México, Mexico

San Miguel Xicalco is a municipal wastewater treatment plant located in the Tlalpan borough of Ciudad de México, Mexico. It serves a population of 4,390 residents, classifying it as a small-scale facility within the densely populated urban area of the capital. The plant provides secondary treatment, which is the standard level required under Mexican regulations (NOM-001-SEMARNAT-1996) for discharge into water bodies. With a designed capacity of 648.00 m³/day and a current discharge volume of 415.58 m³/day, the plant operates below its full capacity, ensuring adequate treatment for its service area. The treated effluent is discharged into the local drainage system, which ultimately flows into the Valley of Mexico basin. This basin is a closed hydrological system, meaning water does not naturally drain to the sea; instead, it is managed through a complex network of canals and tunnels to prevent flooding and convey wastewater to treatment facilities. The plant plays a crucial role in protecting the local environment and public health by reducing pollution in this sensitive urban watershed.

The plant discharges into the Valley of Mexico basin, an endorheic basin that historically contained lakes. Today, the basin's water is managed through artificial drainage to the Tula River and eventually the Gulf of Mexico. The plant's secondary treatment helps reduce organic pollutants and suspended solids, protecting downstream water quality in a region facing significant water scarcity and ecological pressure from urbanization.